phylink,sfp: negotiate interface format with MAC

Negotiate the interface format with the MAC rather than requiring it to
be a fixed type specified solely by the SFP module.  This allows modules
that can work with several different interface signalling formats to
select a format compatible with the MAC - for example, a Fiber module
supporing Gigabit ethernet and faster connected to a Gigabit only MAC
needs to select the 1000BASE-X mode.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 6ac8b29..27327c9 100644 (file)
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1584,25 +1584,14 @@ static int phylink_sfp_module_insert(void *upstream,
        bool changed;
        u8 port;
 
-       sfp_parse_support(pl->sfp_bus, id, support);
-       port = sfp_parse_port(pl->sfp_bus, id, support);
-       iface = sfp_parse_interface(pl->sfp_bus, id);
-
        ASSERT_RTNL();
 
-       switch (iface) {
-       case PHY_INTERFACE_MODE_SGMII:
-       case PHY_INTERFACE_MODE_1000BASEX:
-       case PHY_INTERFACE_MODE_2500BASEX:
-       case PHY_INTERFACE_MODE_10GKR:
-               break;
-       default:
-               return -EINVAL;
-       }
+       sfp_parse_support(pl->sfp_bus, id, support);
+       port = sfp_parse_port(pl->sfp_bus, id, support);
 
        memset(&config, 0, sizeof(config));
        linkmode_copy(config.advertising, support);
-       config.interface = iface;
+       config.interface = PHY_INTERFACE_MODE_NA;
        config.speed = SPEED_UNKNOWN;
        config.duplex = DUPLEX_UNKNOWN;
        config.pause = MLO_PAUSE_AN;
@@ -1611,6 +1600,22 @@ static int phylink_sfp_module_insert(void *upstream,
        /* Ignore errors if we're expecting a PHY to attach later */
        ret = phylink_validate(pl, support, &config);
        if (ret) {
+               netdev_err(pl->netdev, "validation with support %*pb failed: %d\n",
+                          __ETHTOOL_LINK_MODE_MASK_NBITS, support, ret);
+               return ret;
+       }
+
+       iface = sfp_select_interface(pl->sfp_bus, id, config.advertising);
+       if (iface == PHY_INTERFACE_MODE_NA) {
+               netdev_err(pl->netdev,
+                          "selection of interface failed, advertisment %*pb\n",
+                          __ETHTOOL_LINK_MODE_MASK_NBITS, config.advertising);
+               return -EINVAL;
+       }
+
+       config.interface = iface;
+       ret = phylink_validate(pl, support, &config);
+       if (ret) {
                netdev_err(pl->netdev, "validation of %s/%s with support %*pb failed: %d\n",
                           phylink_an_mode_str(MLO_AN_INBAND),
                           phy_modes(config.interface),

diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 1574942..3d4ff5d 100644 (file)
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -106,68 +106,6 @@ int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 EXPORT_SYMBOL_GPL(sfp_parse_port);
 
 /**
- * sfp_parse_interface() - Parse the phy_interface_t
- * @bus: a pointer to the &struct sfp_bus structure for the sfp module
- * @id: a pointer to the module's &struct sfp_eeprom_id
- *
- * Derive the phy_interface_t mode for the information found in the
- * module's identifying EEPROM. There is no standard or defined way
- * to derive this information, so we use some heuristics.
- *
- * If the encoding is 64b66b, then the module must be >= 10G, so
- * return %PHY_INTERFACE_MODE_10GKR.
- *
- * If it's 8b10b, then it's 1G or slower. If it's definitely a fibre
- * module, return %PHY_INTERFACE_MODE_1000BASEX mode, otherwise return
- * %PHY_INTERFACE_MODE_SGMII mode.
- *
- * If the encoding is not known, return %PHY_INTERFACE_MODE_NA.
- */
-phy_interface_t sfp_parse_interface(struct sfp_bus *bus,
-                                   const struct sfp_eeprom_id *id)
-{
-       phy_interface_t iface;
-
-       /* Setting the serdes link mode is guesswork: there's no field in
-        * the EEPROM which indicates what mode should be used.
-        *
-        * If the module wants 64b66b, then it must be >= 10G.
-        *
-        * If it's a gigabit-only fiber module, it probably does not have
-        * a PHY, so switch to 802.3z negotiation mode. Otherwise, switch
-        * to SGMII mode (which is required to support non-gigabit speeds).
-        */
-       switch (id->base.encoding) {
-       case SFP_ENCODING_8472_64B66B:
-               iface = PHY_INTERFACE_MODE_10GKR;
-               break;
-
-       case SFP_ENCODING_8B10B:
-               if (!id->base.e1000_base_t &&
-                   !id->base.e100_base_lx &&
-                   !id->base.e100_base_fx)
-                       iface = PHY_INTERFACE_MODE_1000BASEX;
-               else
-                       iface = PHY_INTERFACE_MODE_SGMII;
-               break;
-
-       default:
-               if (id->base.e1000_base_cx) {
-                       iface = PHY_INTERFACE_MODE_1000BASEX;
-                       break;
-               }
-
-               iface = PHY_INTERFACE_MODE_NA;
-               dev_err(bus->sfp_dev,
-                       "SFP module encoding does not support 8b10b nor 64b66b\n");
-               break;
-       }
-
-       return iface;
-}
-EXPORT_SYMBOL_GPL(sfp_parse_interface);
-
-/**
  * sfp_parse_support() - Parse the eeprom id for supported link modes
  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
  * @id: a pointer to the module's &struct sfp_eeprom_id
@@ -296,6 +234,45 @@ void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 }
 EXPORT_SYMBOL_GPL(sfp_parse_support);
 
+/**
+ * sfp_select_interface() - Select appropriate phy_interface_t mode
+ * @bus: a pointer to the &struct sfp_bus structure for the sfp module
+ * @id: a pointer to the module's &struct sfp_eeprom_id
+ * @link_modes: ethtool link modes mask
+ *
+ * Derive the phy_interface_t mode for the information found in the
+ * module's identifying EEPROM and the link modes mask. There is no
+ * standard or defined way to derive this information, so we decide
+ * based upon the link mode mask.
+ */
+phy_interface_t sfp_select_interface(struct sfp_bus *bus,
+                                    const struct sfp_eeprom_id *id,
+                                    unsigned long *link_modes)
+{
+       if (phylink_test(link_modes, 10000baseCR_Full) ||
+           phylink_test(link_modes, 10000baseSR_Full) ||
+           phylink_test(link_modes, 10000baseLR_Full) ||
+           phylink_test(link_modes, 10000baseLRM_Full) ||
+           phylink_test(link_modes, 10000baseER_Full))
+               return PHY_INTERFACE_MODE_10GKR;
+
+       if (phylink_test(link_modes, 2500baseX_Full))
+               return PHY_INTERFACE_MODE_2500BASEX;
+
+       if (id->base.e1000_base_t ||
+           id->base.e100_base_lx ||
+           id->base.e100_base_fx)
+               return PHY_INTERFACE_MODE_SGMII;
+
+       if (phylink_test(link_modes, 1000baseX_Full))
+               return PHY_INTERFACE_MODE_1000BASEX;
+
+       dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
+
+       return PHY_INTERFACE_MODE_NA;
+}
+EXPORT_SYMBOL_GPL(sfp_select_interface);
+
 static LIST_HEAD(sfp_buses);
 static DEFINE_MUTEX(sfp_mutex);
 

diff --git a/include/linux/sfp.h b/include/linux/sfp.h
index e724d5a..ebce9e2 100644 (file)
--- a/include/linux/sfp.h
+++ b/include/linux/sfp.h
@@ -422,10 +422,11 @@ struct sfp_upstream_ops {
 #if IS_ENABLED(CONFIG_SFP)
 int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
                   unsigned long *support);
-phy_interface_t sfp_parse_interface(struct sfp_bus *bus,
-                                   const struct sfp_eeprom_id *id);
 void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
                       unsigned long *support);
+phy_interface_t sfp_select_interface(struct sfp_bus *bus,
+                                    const struct sfp_eeprom_id *id,
+                                    unsigned long *link_modes);
 
 int sfp_get_module_info(struct sfp_bus *bus, struct ethtool_modinfo *modinfo);
 int sfp_get_module_eeprom(struct sfp_bus *bus, struct ethtool_eeprom *ee,
@@ -444,18 +445,19 @@ static inline int sfp_parse_port(struct sfp_bus *bus,
        return PORT_OTHER;
 }
 
-static inline phy_interface_t sfp_parse_interface(struct sfp_bus *bus,
-                                               const struct sfp_eeprom_id *id)
-{
-       return PHY_INTERFACE_MODE_NA;
-}
-
 static inline void sfp_parse_support(struct sfp_bus *bus,
                                     const struct sfp_eeprom_id *id,
                                     unsigned long *support)
 {
 }
 
+static inline phy_interface_t sfp_select_interface(struct sfp_bus *bus,
+                                                  const struct sfp_eeprom_id *id,
+                                                  unsigned long *link_modes)
+{
+       return PHY_INTERFACE_MODE_NA;
+}
+
 static inline int sfp_get_module_info(struct sfp_bus *bus,
                                      struct ethtool_modinfo *modinfo)
 {